Troubleshooting License Server Issues

Below are some of the most common problems encountered when hosting a license server.

Unsupported Operating System

The license server can be any Linux, Solaris, Mac OSX, or Windows(Vista or newer) system which is accessible from the client that will be running Understand software. Windows XP and Windows Server 2003 are no longer supported. You can mix and match operating systems, for example you can run a client on Windows and use a Linux system as the license server.

Older Versions

Understand 4.0 requires that the license server be upgraded to at least build 772. You can see the license server build number in the upper left section of the GUI or from the command line by running almd -h You can get the latest version from

You will also need an updated license file, you can tell the newer license files because they have a “maintenance” column with the date that the maintenance expires. You can get an updated license file from as long as your maintenance is up to date.

Firewall Ports

By default Understand uses UDP port 9000 to communicate with the License Server. If there are problems, ensure that this port is open on both the client and server. If you’ve changed that port to something else make sure they both match.

Almhostid Changed

The license file is built targeting the Almhostid of the specific server. If a hardware change causes the almhostid to change, a new license will need to be generated. Send the new almhostid to and we will rebuild the license file.

DNS Resolution Problems

Sometimes the client where Understand is installed has problems finding the server. Verify that you can ping the server, or trying specifying the IP address instead of name of the server in both the license file and in the client.

Service Won’t Start

Make sure the user account has permission to start a service/daemon. On Windows when launching the License Manager try right clicking on the shortcut and running as an Administrator.

Sometimes some servers are setup in such a manner that users cannot create services from the command line. This seems to happen mostly on Windows Server 2008. The license manager may appear to start, but a check in the services list does not show the “SciTools License Manager” Service. The work around for this is to create a scheduled task to launch the License Manager at machine startup instead of using services. More details here (

Delete Licenses on Client

Sometimes the client can hold on to an invalid license. In the client, try hitting the “Delete All Licenses” button in the licensing dialog, and then re-entering the name of the license server.

Still Not Working?

If none of those options are successful the next step is to simulate a connection and send us the log files.

Server Logging Setup

On the server side run this command to start the server with licensing enabled.
almd -d 3 -f path/to/serverlog.txt -l path/to/license.dat

Client Logging Setup

On the client side first create a file with the server connection information in the Understand Installation folder (i.e. SciTools\conf\license\license.dat)
It needs to have this line in it (replacing ServerIP with the actual IP address of the license server)
Server: ServerIP 00000000 8998

Next run this command from the command line to simulate a connection to the license server.
almtest -d 3 -f path/to/clientlog.txt

Then send the serverlog.txt and clientlog.txt files to

Hopefully analyzing the communication between the two will help us determine what is wrong.